Conventionally, a control apparatus of an internal combustion engine that can detect a cylinder in which increased torque fluctuation due to overmuch inside EGR arises is disclosed in, for example, under listed patent document 1. More particularly, according to the invention disclosed in patent document 1, a cylinder in which overmuch inside EGR arises can be detected based on torque fluctuation of each individual cylinder and intake pressure, which varies according to an inside EGR quantity in each individual cylinder.